<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>纯css写一个简约好看的质感方块</title>
  <style>
    html, body {
      width: 100%;
      height: 100%;
      display: flex;
      justify-content: center;
      align-items: center;
      background-color: #acbaca;
    }
    .block {
      width: 300px;
      height: 300px;
      background-color: #c9d5e0;
      border-radius: 50px;
      box-shadow: 30px 30px 30px -10px rgba(0, 0, 0, 0.15),
                  inset 15px 15px 10px rgba(255, 255, 255, 0.75),
                  -15px -15px 35px rgba(255, 255, 255, 0.55),
                  inset -1px -1px 10px  rgba(0, 0, 0, 0.2);
      /* box-shadow: 阴影位置 x轴偏移 y轴偏移 模糊半径 扩展半径 颜色 */
    }
  </style>
</head>
<body>
  <div class="block"></div>
</body>
</html>